As an example of a known portable electronic device, it has been proposed to provide a digital camera with a touch panel on the upper face of a crystal monitor, the touch panel being capable of detecting a contact position and a pressure magnitude, and to provide different instructions to a camera operation system in accordance with the contact position on the touch panel and the magnitude of the pressure (for example, see Patent Literature 1). Furthermore, in recent years, a variety of mobile phones and smartphones having a display screen and a touch panel that cover nearly an entire surface of the device have been proposed.